chore: add unit tests for CRAP report formatting functions

[yvonnedevlinrh]

Context

Four report formatting functions in internal/crap/ were extracted during the q4-complexity-reduction work (decomposition of crap.WriteText from CC 18 to CC 2). The extracted helpers are small, focused functions with zero direct test coverage. Adding tests for these functions improves confidence in report output correctness and prevents regressions.

Related: codebase audit from #166 triage

Functions

Function	File	Lines	Description
writeScoreTable	internal/crap/report.go	~36	Renders the CRAP score table with columns for CRAP, complexity, coverage, function name, and location
writeWorstSection	internal/crap/report.go	~32	Renders the "Worst Offenders" section with fix strategy labels
writeRemediationSection	internal/crap/report.go	~13	Renders the "Remediation Breakdown" section with strategy counts
writeSSADiagnostics	internal/crap/report.go	~11	Renders SSA degradation warnings listing affected packages

Approach

All four functions write to an io.Writer and accept structured data (slices of crap.Score, crap.Summary). Tests should:

• Construct synthetic Score and Summary values
• Call each function with a bytes.Buffer
• Assert the output contains expected column headers, values, and formatting
• Verify 80-column width compliance (per project convention)

Acceptance Criteria

• Each function has at least one unit test verifying its primary output
• Tests use synthetic data (no real CRAP analysis required)
• Output width verified to fit within 80-column terminals
• All tests run without testing.Short() guards
• go test -race -count=1 -short ./internal/crap/... passes
• golangci-lint run reports zero issues